Anti-friction support



J. J. SLOYAN ANTI-FRICTION SUPPORTk May 6, 195s 2 Sheets-Sheel'I l lFil'ed March 8, 1954 l, INVENTOR FPU/V- 510W BY /Mwv/ P ATTORNEY May 5,1958 J. J. SLYAN 2,833,598

ANTI-FRICTION SUPPORT Filed March 8, 1954 2 Sheets-Sheet 2 INVENToRJFw/vff Mw/V.

I BY 7.3%.

ATTORNEY United Sttes Patent ANTI-FRICTION SUPPORT Jeromel J. Sloyan,Trenton, N. J.

Application March 8, 1954, Serial No. 414,771 4 Claims. (Cl. 308-6) This`invention relates to slidable supports and more particularly to thattype such `as is shown in my prior application S. N. 117,999, ledSeptember 27, 1949, now Patent No. 2,762,663, wherein a carriage isprovided having a limited movement longitudinally of a track or rail.

Both the invention of said prior application and of the presentdisclosure have utility in association with various instrumentalities ofdiverse character of which reciprocating tables for milling machines,typewriter carriages, motor supports, gun recoil mounts and otherdevices will sutlice as illustrative, and of which themotor support hasbeen arbitrarily selected for purpose of specific showing in theaccompanying drawings. The essential characteristie of the support ofthe present invention and of the prior application common to thenumerous uses, is that the movable portion or carriage has linearmovement within maximum limits and must slide with.minimum frictionthroughout the prescribed range of its permitted reciprocation. l

It was pointed out in the previous application, 'and is equally truewith respect to the present disclosure, that the structure involvedshall have a capability of free operation under severe load conditionsand readily respond to sudden and quick shifts of load or position ofthecarriage on the rails. An example equally applicable here as in theprior application is the now commonplace employment of motor driveninstrumentalities which are belt driven and in which the tension of thebelt or adjustment of the belt for purpose of speed differential areoftenfprovided. As a specific example, I mayY again refer tothe popularvariable speed ydrive using a V-shaped belt with pulleys correspondinglygrooved, of which one, and usually the driving pulley, is constructed insuch manner that its pitch diameter can be varied at will withoutstopping the motor. That pulley is essentially two cones, or frustrumsof cones axially aligned and spring loaded toA keep the groove formedthereby for belt` engagement of maximum pitch diameter, but with thecones adapted to'be slid one from the other by tension applied to thebelt wedging thebelt deeper between the cones and thus obtaining beltengagement at a less diametrical distance from the cone axis. Thewedging of the belt is accomplished by displacing the motor further fromthe driven instrumentality. It is consequently essential that the motormaybe moved readily since the speed control of the driveninstrumentality is a function of motor location and change of locationof the driving and driven pulleys with respect to each other. y

v*Common to the prior application and to the present invention is theutilization of a fixed rail upon which is mounted a longitudinallymovable glider, constituting a part of the carriage, with series ofballs interposed at 1ongitudinal corners of the glider between theglider and rail for the purpose of providing anti-,frictionreciprocation of the glider on the rail. In both instances, eachlongitudinal corner of the glider constitutes a raceway fora series ofballs, but the raceway is not completely lled with balls,

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2 A thus providing voids of adequate length to permit the balls to rollvfor the necessary distance to accommodate the range of displacement orlongitudinal movement ofthe glider with respect to the rail.Theoretically, thedisplacement of the balls in rolling is substantiallyhalf of lthe longitudinal displacement of the glider with respect to therail, but actually varies slightly from this theoretic dimension sincethe balls do not ride on the glider surface directly diametrically tothe riding of the balls on the-rail. Since this difference is smallcompared to the actual distance of transition of the balls, thedescription, fork simplicity, will refer to the displacement of theballs as substantially half of the displacement of the glider.

Both the prior application and the present disclosure utilize end caps56von the glider for purpose of confining the ends of the raceways andthereby intended to keepfthe balls always between the -glider and therail. Under what may be termed ideal circumstances, namely, where apreloading condition exists, the relative positions of the balls, railsand gliders, when once properly arranged, would be maintained due to thefact that the balls would always be under compression and held in placein rolling contact with4 both the glider and rail. However, this idealcondition does not always exist, and the present invention proposes1corrective measure therefor. The absence of the ideal condition may beexplained as resulting, for instance, by unavoidable presence, undereconomical manufacturing exigencies, of appreciable clearance actuallyexisting between one or more of the series of balls and the rail surfaceand raceway.

Suppose, for example, that preloading of all series of balls between theraceways and rail had not been accom- `plished (which is generallytrue), and the support is mounted or used with the rails standingvertically, it is probable that the balls would drop, not roll to thelower end of the rider, and if the support were inverted, the ballswould drop to the other end of the rider'. In either event, if theoperation then requires the glider to move upward, the balls should becapable of rolling downward with respect to the glider, but actuallywould not be able to do so since they are already against the bottom endcap, and consequently would not function as anti-friction devices andmight indeed force the end cap off of the glider and spill the balls.Again, suppose the balls had for some yreason acquired a position at oneend of the -glider and kthe support is, nevertheless, used with the railand glider positioned horizontally, the same adverse condition wouldagain prevail when the glider attempts to move in a direction away fromthe end of the rail where the balls are assembled.

Where only the weight of the rider and the motor or other piece ofmachinery mounted thereonis considered, only the upper series of ballswould be alected by the downward gravitational force, but since the belttension applies a tilting force longitudinally of the glider, aresultant pressure in practice will be applied to some of the balls ofthe upper series and to some of the balls of the lower series.Consequently, under this set of circumstances, there is a requirementfor the balls of all of the series to roll toward the end cap locatednext to the ends of the several series ot improperly situated balls,thus resulting in a great liklihood of the balls forcing the retainingcap ofi of the end of the glider.

The situations above described might well happen in the ordinary courseof events. For example, while a support having a construction of myprevious application is transported, like all freight, it is manhandledand at leastgsubjected to vibration and jolts, and if the balls areloose in their raceways (and it is more than likely that they will be)they might easily find their way to .one end `of the.. glider, and guitepossibly to the endmostimdesirable for operational` purposes and detri5mental to` the proper functioning and assembly of the balls` in theglider.

In `addition to .the broad concept oftheinvention yof proposal `to`provide corrective, measures t `for the im-` proper operation andIdetrimental effects, Athe Yinvention contemplates 1an inherent controlfor location `of the series of'balls in the raceways of the glider.

:Somewhat more specifically, the invention provides for maintaining theseries of balls in a spaced relation from theend caps vuntil positivelymoved toward one ortheother end cap in normal-operation of the glider'.

A further yobject of theinvention is to `avoid uninten-` tionaldisplacement of `the Aballs' from desired relation thereof tof theglider.

Yet another object of the invention is to provide means normallylocatingthe balls -awayfrom theends ofA the raceways and preferably evenly fromboth ends, `until positively actuated in use toward `one end or `theother by movement of the glider.

Another object of the invention is to hold the balls yieldably in the`preferred location `so as to be loperationally movable therefrom bymovement of Vthe glider.

VOther objects of the invention will appear to per sons skilled in theart to which it appertains as .the description proceeds, bothby directrecitation thereof and 'by implication from the context.

Referring to the accompanying drawings, in which like `numerals ofreference indicate similar partsthrough-- out the several views; lFigure 1 is a side elevation of the `support of my invention, upon whichis carried a motorfhaving a belt drive to a driven instrumentality;

Figure 2` is a plan `of said support of my invention;

Figure 3 is a longitudinal sectional view of a `glider in operativeposition upon aprail `and showing my invention incorporated therewith,the section being takn upon two planes as indicated by line III-III ofFig.` 4;

Figure 4 is a cross-section on line IV-IV of Fig. 3;

Figure 5 is a longitudinal sectional view similar to Fig. 3, and showingthe glider as moved to one'end of its range of movement as occurs inoperational Vuse of the support;

Figure `6` is another longitudinal section of the character of Fig. v3,andshowing another modicetion wherein the balls are retained in.associated relation by a clip; l

Figure 7 is a cross-section .on line YlI-VJI of Fig. 6;. and

Figure 8 is a perspective view o f said clip.

As an arbitrarily selected exemplication of the invention in one usethereof, the general organization of Fig. l illustrates an electricmotor 3() driving `any vdesired instrumentality 31 through the agency ofa belt 32 and pulleys 33 and 34, said pulleys being respectively 0ntbeshafts of said `motor and instrumentality. 'The pulley 34 on themotor` istshown of the known type which expands and rcontracts in anaxial direction for locating the belt at a desired pitch circle .of thePulley for speed variation of drive for.y the pulley of the fixedinstrumentality. In general, the motor is representative of a movableor' adjustable mechanism.

The present invention resides primarily in the `oon,- struction of asupport35 for thesaid mechanism, As show-n, a bed 36 is provided .towhich the fixed `instrumentality is secured and Ato which a fixedportion Vof the support of the present invention is also secured, itbeing understood that said bed .is representative of any structure -suchas a floor, table, wall, shelf, ceiling' or the like jwhich will affordrelatively ltilted mounting for the aforementioned fixed instrumentalityand iixed portion of the support.

p The fixed portion of the support as herein illustrated comprises twoparallel rails 37v ,the ends of which are made fast to transverse cleats38 which may conveniently be. formed from appropriate lengths of angleiron .one ilang'e of which forms a foot resting upon and adapted to besecured to bed 36 and the other ange `of which standsperpendicularlyvand constitutes an end abutment and rigid support forthe said rails. The assembly of rails and cleats forms a rectangle ofwhich the cleats will be arbitrarily referred to as at the ends and therails as at the sides of the rectangular assembly constituting the fixedor basal portion of the support.

The movable portion of the support comprises a carp riage 39 havingslidable movement-longitudinally of the rails, said carriage havinggliders 40 at its opposite side margins cooperating with the rails tonot only provide for sliding of the carriage on the rails, but to alsokeep the carriage assembled upon the rails. Each rail has across-sectional configuration differing from that of the glider of suchcharacter that longitudinal raceways for anti-frictiou means, such asballs 41 are provided between the `rails and gliders.` As shown, therails have a circular cross-section and the `gliders are rectangular incross-section so that the` raceways are` constituted at the longitudinalcorners of the gliders. The carriage has a limited longitudinalmovement, the range or am-y plitude thereof being confined by engagementof the ends .of the carriage against the upright flanges of cleats 38 orother suitable stop.

It is essential that the balls 41 `be free to roll, since if preventedfrom rollingthey merely serve as inert inserts between the rail andglider and as such would provide literally `substantially the sameamount of friction as if the glider directly engaged the rail. Since thenormal displacement of the balls along the rail will be substantiallyequal to one half of the displacement of the glider along `the rail andin the same direction as the displacement of the glider; and since thedisplacement of the ballsalong the glider willbe substantially equal toone'half of the displacement of the glider, but in a direction opposedto the direction in which the glider is displaced, voids are providedinthe races to provide more than a sufficient space lengthwise of theraces/to enable the balls to roll without interruption for the fulldisplacement ofthe glider on the rail between its limiting stops.

Preferably terminating each end of each glider, is an end cap 56 whichis hollow and fixed in any suitable manner `upon the glider andperforate at its outer end to slidably pass the rail therethrough.Suitable packing 58 may be included within the end cap so that lubricantmany be retained within the glider.

Yieldable means 59 are provided within the glider next to the endsthereof for centralizing the balls 41 as agroup or series lengthwise ofthe glider. According to they showing herein, the yieldable meanscomprises a thepacking within theend caps.

' raceways.

coil spring in a void at each end of each raceway. Thus with therectangular cross-section of glider shown in those `figures, there willbe four springs at each endl The `far ends of these springs bear againstIn Figures 3, 4 and 5, the inward ends of the springs bear against theend ball of theseries of balls in the several raceways, Vsaid springshaving a diameter substantially the same as the diameters of the ballsso as to function freely in the The strength of each spring is chosen to`be able to support the weight of the series of balls in the racewaywithout materially compressing the spring should of the glider.

the gliderfibe'pstood vertically, but capable of being com-V` pressed bythe push applied bythe balls when A rolling underinuence of longitudinaldisplacement of the glider with respect to rail in .operation of thedevice.

The modication of Figures 6 to 8 has some practical t i advantages overthe other `constructions shown, particu-V larly ,for larger sizes ofsupports.

This embodiment in-` cludS vProvision of a clip 4or spiderfframe 60which is just long enough' to accommodate the several series of balls 41between end plates 61 of the clip. Said end plates are held in ixedparallel relation one to the other by slats 62 which are located betweenthe rail and glider in parallelism thereto. The springs, such as S9, ateach end of the glider bear against plates 61 and have appropriatestrength as a yieldable means at each end of the glider which willsupport the weight of the clip and the several series of balls shouldthe glider be positioned vertically. It may also be appropriate to nowstate that in all forms shown, the voids of the raceways not onlyaccommodate the rolling requirements for the series of balls, but alsoaccommodate the springs so that the springs will not prevent fullamplitude of ball movement.

At the time of assembly of the support of this invention, all of theseries of balls are arranged to occupy the centralized portions of theraceways, `and the glider is located at the mid poistion between itsstops. Then in use, the balls have the necessary voids for travel ineither direction as the glider travels to its destination. Since thedevice rarely has a use where the applied force is purely agravitational vertical force, but is usually a combination of forcescomprised, for instance, by weight of the motor, reactive torque, forcedue to projection of the motor shaft, pull on the pulley, and so forth,and thus all of the series of balls will be somewhere under compressionbetween the glider and rail and will all be subjected to rolling actionwhen the glider moves. However, there may be instances, momentarily orother- Wise, when one or two of the series of balls or portions of theseries are not under compression. This therefore presents a possibilityof the balls in one or more of the series of balls in Figs. 3 to 5 notrolling in agreement with the balls of another series. To avoid thispossibility, the constructions of Figs. 6 to 8 have an advantage ofapplying impetus to any series in which the balls are loose to causethat series to likewise be moved when another series is forced to roll.

I claim: Y

1. A support comprising a cylindrical rail, a rectangular glider movablelongitudinally of said rail, said glider havingfour walls contiguouspairs of which form corners 6 and provide corner spaces between saidglider and rail thereby constituting a plurality of longitudinalraceways, series of balls in said raceways with the balls in eachraceway contacting the said contiguous walls of the glider thereat andcontacting the cylindrical surface of said rail, and each said seriesbeing of less length than the respective raceway containing the seriesof balls and leaving voids at both ends of each series of balls, andyieldable means /in the ends of said raceways entirely within said voidsand maintained aligned each with its series of balls by connement in itsrespective` raceway, said yieldable means adapted to apply forceseffective on the ends of said series of balls in said raceways andlongitudinally of and aligned with each of said series of balls.

2. A support in accordance with claim 1, wherein said yieldable meanscomprises an individual longitudinally coiled spiral spring entirely ineach said void, the diameter of said spring being substantially equal tothe diameters of said balls.

3. A support in accordance with claim l, wherein each said yieldablemeans is effective upon only a single series of balls located in thesame raceway in which said spring is located.

4. A support in accordance with claim 1, wherein a clip is providedcommon to all of the series of balls and locating all of said series ofballs simultaneously at the same longitudinal position on said rail andin said glider, and wherein said yieldable means at correspondingv endsof. said series of balls apply cumulative force at an end of said clip.

References Cited in the tile of this patent UNITED STATES PATENTS

